HVAC BTU calculator
~20 BTU/sqft baseline.
How to use HVAC BTU calculator
- Enter your room's square footage.
- The tool estimates required cooling capacity using a baseline of roughly 20 BTU per square foot.
Limitations
- This baseline doesn't account for ceiling height, insulation quality, sun exposure, or climate zone — for an actual HVAC install, get a proper Manual J load calculation from a contractor.
About this tool
HVAC BTU calculator is a single-purpose utility on instant.tw, a free toolbox of calculators, converters, generators, and quick lookups. Everything works in your browser — nothing is uploaded, nothing is stored on a server unless explicitly noted.
Category: Home & DIY. Browse more Home & DIY tools.